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C-reactive protein (CRP) by turbidimetry (serum/plasma)

Published: August 9, 2026Updated: August 16, 2026

This test measures the level of C-reactive protein, a protein produced by the liver in response to inflammation or infection in your body.

Quick summary

["CRP helps doctors assess inflammation, infection, or risk of future health issues like heart disease."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
26980-3
Short code
C immitis Ab Titr Ser ID
Synonyms
C immitis Ab Titr Ser ID
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
immune-diffusion
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your doctor may order a CRP test to check for signs of inflammation, monitor conditions like arthritis, heart disease, or infections, or evaluate responses to treatments. It can also help identify risks for conditions like heart disease or certain cancers.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm to draw blood. If you’re taking blood from your own arm, follow your healthcare provider’s instructions carefully. Avoid eating or drinking for 8–12 hours before if specified.

What Happens During the Test

A healthcare professional will clean your arm and insert a needle to collect blood into a tube. The process usually takes a few minutes. You may feel a brief pinch, but most people tolerate it well.

What the Results Mean

Results are interpreted by your doctor based on your overall health, symptoms, and medical history. Higher than normal levels may indicate inflammation, infection, or other health concerns.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

CRP Level

Frequently asked questions

How often should I get this test?
Your doctor will determine the frequency based on your health needs. Some people get it yearly for heart health checks, while others may need it more often if they have conditions like arthritis or heart disease.
Can I eat or drink before this test?
Check with your doctor or lab for specifics, but generally, avoid food/drinks for 8–12 hours before if fasting is required. If not, no restrictions apply.
What does a low CRP level mean?
Low CRP levels may suggest minimal inflammation, but they don’t rule out all causes. Your doctor will consider other factors, like symptoms and test results, to interpret results accurately.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy